Bone Mineral Density Corrected for Size in Childhood Leukaemia Survivors Treated with Haematopoietic Stem Cell Transplantation and Total Body Irradiation.

BACKGROUND

Childhood leukaemia survivors treated with haematopoietic stem cell transplantation and total body irradiation (HSCT-TBI) have multiple risk factors for reduced bone mineral density (BMD) and growth failure; hence, BMD assessment must take body size into consideration. This study aimed to evaluate size-corrected BMD in leukaemia survivors treated with and without HSCT-TBI.

METHODS

Childhood leukaemia survivors treated with HSCT-TBI (n = 35), aged 17.3 (10.5-20.9) years, were compared with those treated with chemotherapy only, (n = 16) aged 18.5 (16.1-20.9) years, and population references. Outcome measures included anthropometric measurements and BMD by dual-energy X-ray absorptiometry. BMD was corrected for size as bone mineral apparent density (BMAD). Statistical analysis was performed by 1- and 2-sample t tests as well as regression analysis (5% significance).

RESULTS

HSCT-TBI survivors were lighter and shorter with reduced spinal heights compared with chemotherapy-only subjects and population references. Compared with population references, HSCT-TBI survivors showed lower BMD standard deviation scores (SDS) (p = 0.008), but no difference in BMAD-SDS, and chemotherapy-only survivors showed no differences in neither BMD-SDS nor BMAD-SDS. All HSCT-TBI participants with BMD-SDS <-2 had BMAD-SDS >-2. BMAD-SDS was negatively associated with age (r = -0.38, p = 0.029) in HSCT-TBI survivors.

CONCLUSIONS

Size-corrected BMD are normal in HSCT-TBI survivors in young adulthood, but may reduce overtime. BMD measurements should be corrected for size in these patients to be clinically meaningful.